Portable products such as radio transceivers and pagers can include tilt switches to detect whether the portable product is in a non-vertical position or jitter switches to detect slight movements in the portable product. The tilt switches, also known as man down switches, are typically used on portable products such as transceivers by police officers and watchmen and in hazardous conditions such as correctional institutions, prisons, and mines. Presently, mercury switches are used to detect tilt angles on radios and other portable products. Another variety of the tilt switch, the jitter switch, can detect whether the user of a portable product is motionless, indicating that the user may be in danger or dead, but still in a substantially upright position. In a jitter switch, the lack of motion would typically cause the transmission of a coded alert signal that is processed by a computer and displayed for a dispatcher who would be informed as to the identification and approximate position of the motionless user (horizontal user in the case of a tilt switch).
The use of mercury in tilt and jitter switches present several disadvantages. In a market where products continue to get smaller, the use of mercury impedes this trend. Mercury switches are relatively large for use in smaller sized portable electronic communication devices. Mercury switches also limit the angle of the contact closure. This limit in structure of the mercury switches often presents problems in fitting the switches in spaces that are unaccommodating to such structures. Furthermore, the inherent danger of the use of mercury is ever present for the manufacturers and users of such switches. The small number of manufacturers of miniature mercury switches may be an indication of these inherent problems.